1. Technical Field
The present disclosure relates to an anvil assembly for use with a stapler. More specifically, the present disclosure relates to an anvil assembly having an improved cut ring particularly suited for use with a surgical stapler.
2. Background of Related Art
Anastomosis is the surgical joining of separate hollow tissue organ sections such that the hollow tissue organ sections communicate with each other. Typically, anastomosis follows surgery in which a diseased or defective section of hollow tissue is removed and the remaining end sections are to be joined. In a circular anastomosis procedure, the two ends of organ sections, e.g., the colon, are joined by means of a stapling instrument which drives a circular array of staples through the end sections of each organ section and simultaneously cores any overlapping tissue to free a tubular passage. Coring is effected by translation of an annular knife blade through the overlapping tissue.
Generally, a diseased or defective section of hollow tissue is removed using a linear stapling device which simultaneously cuts the hollow tissue and provides one or more linear rows of staples or fasteners on each side of the cut. The staples or fasteners seal the cut ends of the hollow tissue sections. This operation is performed on each end of the diseased or defective tissue such that each end of the diseased or defective hollow tissue and each end of the hollow tissue sections is sealed. Subsequently, a circular anastomosis stapling or fastener applying device is used to join the ends of the remaining hollow tissue sections and to core overlapping tissue.
The use of cut rings in anvil assemblies of circular anastomosis stapling or fastening devices are well known. Cut rings provide an abutment surface into which the annular knife blade of a circular anastomosis stapler abuts and/or penetrates during firing of the stapler to enhance cutting of tissue. Typically, cut rings are formed of a soft material, e.g., polyethylene, to allow some degree of knife penetration into the cut ring. During an anastomosis procedure, staples may inadvertently become positioned between the annular knife blade and the cut ring. In conventional staplers, because the cut ring is formed of a soft material, contact between the knife blade and a staple typically presses the staple into the cut ring and does not effectuate cutting of the staple.
Accordingly, a need exists for an improved surgical stapler which can not only effectively cut tissue but also effectively cut through existing staples in the tissue.